Heat box of chicken broth in large pan on the stove over medium/high heat.
Add spinach when it starts to steam.
Cook spinach until it becomes limp (2 minutes).
Pour spinach and broth into a food processor or blender, add seasoning and put lid on.
Blend over medium speed until smooth.
Pour back into pan and warm over low heat.
Turn off heat and stir in half and half.
Serve warm or cold on a hot summer day.